IR 05000443/2019010
| ML19184A010 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 07/03/2019 |
| From: | Mel Gray NRC Region 1 |
| To: | Nazar M NextEra Energy Seabrook |
| References | |
| IR 2019010 | |
| Download: ML19184A010 (21) | |
Text
July 3, 2019
SUBJECT:
SEABROOK STATION UNIT 1 - DESIGN BASES ASSURANCE INSPECTION INSPECTION REPORT 05000443/2019010
Dear Mr. Nazar:
On June 5, 2019, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Seabrook Unit 1 and discussed the results of this inspection with Mr. Eric McCartney, Site Vice President and other members of your staff. The results of this inspection are documented in the enclosed report.
Three findings of very low safety significance (Green) are documented in this report, all of which involved violations of NRC requirements. We are treating these violations as non-cited violations (NCV) consistent with Section 2.3.2.a of the Enforcement Policy.
If you contest the violations or significance or severity of the violations documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region I; the Director, Office of Enforcement; and the NRC Resident Inspector at Seabrook.
If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region I; and the NRC Resident Inspector at Seabrook. This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely,
/RA/
Mel Gray, Chief Engineering Branch 1
Docket No.: 50-443 License No.: NPF-86
Enclosure:
Inspection Report 05000443/2019010
Inspection Report
Docket Number:
05000443
License Number:
Report Number:
Enterprise Identifier: I-2019-010-0050
Licensee:
NextEra Energy Seabrook, LLC
Facility:
Seabrook Station Unit 1
Location:
Seabrook, NH 03874
Inspection Dates:
April 14, 2019 to May 04, 2019
Inspectors:
S. Pindale, Senior Reactor Inspector (Team Leader)
J. Ambrosini, Senior Emergency Preparedness Inspector
F. Arner, Senior Reactor Analyst
M. Orr, Reactor Inspector
J. Schoppy, Senior Reactor Inspector
C. Baron, NRC Mechanical Contractor
J. Nicely, NRC Electrical Contractor
Approved By:
Mel Gray, Chief
Engineering Branch 1
Division of Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees
performance by conducting a design bases assurance inspection at Seabrook Unit 1 in
accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs
program for overseeing the safe operation of commercial nuclear power reactors. Refer to
https://www.nrc.gov/reactors/operating/oversight.html for more information.
List of Findings and Violations
Improperly Sized Thermal Overload Relays for Throttling Motor-Operated Valves
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
Open
None
The team identified a finding of very low safety significance (Green) involving a Non-Cited
Violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, in that NextEra did
not adequately verify or check the adequacy of design, such as by the performance of design
reviews, by the use of alternate or simplified calculational methods, or by the performance of
a suitable testing program for several motor-operated valves (MOV). Specifically, NextEra
did not verify the thermal overload (TOL) protective devices on eight safety-related
emergency feedwater flow control MOVs were properly sized to support their safety function
of repetitive jogging/throttling during transients and postulated events.
Inadequate 4kV Breaker Testing
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
Open
None
The team identified a finding of very low safety significance (Green) involving a Non-Cited
Violation of 10 CFR Part 50, Appendix B, Criterion XI, Test Control, in that NextEras test
program did not assure that all testing required to demonstrate that structures, systems, and
components will perform satisfactorily in service in accordance with written test procedures
that incorporate the requirements and acceptance limits contained in applicable design
documents. Specifically, NextEras six-year inspection, testing and preventive maintenance
procedure for 4kV safety-related breakers did not perform as-found electrical testing for
breaker functions prior to performing preventive maintenance activities. As such, breaker
degradation while in service may not be identified during the subsequent testing, and could
prevent the identification of deterioration toward an unacceptable condition.
Survivability of Equipment during a Postulated Design Basis Accident Coincident with
Degraded Offsite Power System Voltage
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
Open
None
The team identified a finding of very low safety significance (Green) involving a Non-Cited
Violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, in that NextEra did
not verify or check the adequacy of design for setting thermal overload (TOL) protective
devices, such as by the performance of design reviews, by the use of alternate or simplified
calculational methods, or by the performance of a suitable testing program. Specifically,
NextEra did not ensure that TOL protective device settings for specific motor-operated valves
(MOVs) would prevent safety-related loads from becoming damaged or unavailable during a
postulated design basis event involving a loss-of-coolant accident coincident with a degraded
voltage of the offsite power supply system.
Additional Tracking Items
None.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IP) in
effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with
their attached revision histories are located on the public website at http://www.nrc.gov/reading-
rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared
complete when the IP requirements most appropriate to the inspection activity were met
consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection
Program - Operations Phase. The inspectors reviewed selected procedures and records,
observed activities, and interviewed personnel to assess licensee performance and compliance
with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY
71111.21M - Design Bases Assurance Inspection (Teams)
The team evaluated the following components, permanent modifications, and operating
experience during the weeks of April 15, 2019, and April 29, 2019.
For the components, the team reviewed the attributes listed in Inspection Procedure 71111.21M, Appendix A, Component Review Attributes, such as those listed
below. Specifically, the team evaluated these attributes as per 71111.21M, Appendix B,
Component Design Review Considerations and 71111.21M, Appendix C, Component
Walkdown Considerations.
Design Review - Large Early Release Frequency (IP Section 02.02) (1 Sample)
Containment Recirculation Sump A Isolation Valve, 1-CBS-V8
Normal, abnormal, and emergency operating procedures
Consistency among design and licensing bases and other documents/procedures
System health report, maintenance effectiveness and records, and corrective action
history
Design calculations
Surveillance testing and recent test results
Testing of control system interlocks
Diagnostic testing methodology
Adequacy of electrical power supply for motor and controls
Thermal overload protection settings
The team used Appendix B guidance for Valves, Instrumentation, Electric Loads, and As-
Built System.
Design Review - Risk-Significant/Low Design Margin Components (IP Section 02.02) (5 Samples)
(1)
A Primary Component Cooling Water Pump, CC-P-11-A
Material condition and installed configuration (e.g., visual
inspection/walkdown)
Normal, abnormal, and emergency operating procedures
- Consistency among design and licensing bases and other documents and
procedures
System health report, maintenance effectiveness and records, and corrective
action history
Control logic (pump trip)
Equipment/environmental controls and qualification
Design calculations
Surveillance testing and recent test results
The team used Appendix B guidance for Valves, Instrumentation, Electric Loads, and
As-Built System.
(2)
Service Water Train A Isolation of Secondary Loads, SWS-MOV-V4
Material condition and installed configuration (e.g., visual
inspection/walkdown)
Normal, abnormal, and emergency operating procedures
Consistency among design and licensing bases and other
documents/procedures
System health report, maintenance effectiveness and records, and corrective
action history
Design calculations
Adequacy of electrical power supply for motor and controls
Thermal overload protection settings
Surveillance testing and recent test results
The team used Appendix B guidance for Valves, Instrumentation, Electric Loads, and
As-Built System.
(3)
4160Vac Bus E5 and associated Emergency Diesel Generator A (electrical)
Material condition and installed configuration (e.g., visual
inspection/walkdown)
Normal, abnormal, and emergency operating procedures
Component health report, maintenance effectiveness and records, and
corrective action history
Coordination and interface with the transmission system operator
Design calculations (e.g., load flow, bus loading and voltage drop,
environmental temperature effects, degraded and loss of voltage protection,
protective relay and breaker settings and coordination, short circuit/breaker
duty analysis, and diesel generator loading)
Surveillance testing and recent test results
The team used Appendix B guidance for Instrumentation, Circuit Breakers and Fuses,
Cables, Electric Loads, Motor Control Centers (MCCs), and As-built system.
(4)
Supplementary Emergency Power System (Diesel Generator) Train A
Material condition and installed configuration (e.g., visual
inspection/walkdown)
Normal, abnormal, and emergency operating procedures
- Consistency among design and licensing bases and other documents and
procedures
System health report, maintenance effectiveness and records, and corrective
action history
Design calculations (e.g., emergency diesel generator loading, voltage drop
analyses)
Surveillance testing and recent test results
Equipment protection from fire, flood, and water intrusion or spray
Heat removal cooling water and ventilation
Energy sources, fuel and air (e.g., engine start, operation, and control)
The team used Appendix B guidance for Valves, Pumps, Instrumentation, Electric
Loads, and As-Built System.
(5)
Turbine-Driven Emergency Feedwater Pump, FW-P-37A
Material condition and installed configuration (e.g., visual
inspection/walkdown)
Normal, abnormal, and emergency operating procedures
Consistency among design and licensing bases and other
documents/procedures
System health report, maintenance effectiveness and records, and corrective
action history
Design calculations
Surveillance testing and recent test results
Turbine overspeed protection
Pump steam binding protection
Exhaust stack tornado missile protection
Station blackout environmental conditions
The team used Appendix B guidance for Valves, Instrumentation, and As-Built
System.
Modification Review - Permanent Modifications (IP Section 02.03) (5 Samples)
(1)
EC 145024, Reconciliation of Methods Used for Determining RWST Minimum
Submergence Levels to Preclude Vortexing, Revision 0
(2)
EC 145372, EDG Lube Oil High Temperature Trip Setpoint Change, Revision 2
(3)
EC 284280, Increase in RCS Loop Tavg to Average Tavg Deviation Alarm Setpoint,
Revision 0
(4)
EC 291333, RC-V-122/124 Allowable Closure Time Increase, Revision 0
(5)
EC 287636, Diesel Air Handling Calculation MSVCS-FAG-09, Revision and Service
Environment Chart Update, Revision 0
Review of Operating Experience Issues (IP Section 02.06) (2 Samples)
(1)
NRC Information Notice 2005-30, Safe Shutdown Potentially Challenged by
Unanalyzed Internal Flooding Events and Inadequate Design, dated
November 7, 2005
(2)
NRC Information Notice 2016-05, Operating Experience Regarding Complications
from a Loss of Instrument Air, dated April 27, 2016
INSPECTION RESULTS
Improperly Sized Thermal Overload Relays for Throttling Motor-Operated Valves
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
Open
None
The team identified a finding of very low safety significance (Green) involving a Non-Cited
Violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, in that NextEra did
not adequately verify or check the adequacy of design, such as by the performance of design
reviews, by the use of alternate or simplified calculational methods, or by the performance of
a suitable testing program for several motor-operated valves (MOV). Specifically, NextEra did
not verify the thermal overload (TOL) protective devices on eight safety-related emergency
feedwater flow control MOVs were properly sized to support their safety function of repetitive
jogging/throttling during transients and postulated events.
Description: The team noted that the safety-related emergency feedwater flow control MOVs
FW-FV-4214A/B through FW-FV-4244A/B (eight valves) have a design function for repetitive
jogging/throttling during transients and postulated design basis events. In calculation
9763-3-ED-00-28-F-CALC_009, NextEra selected TOLs based on the MOVs having three
normal strokes to provide capability to recover from a mis-positioned MOV and provide
protection of the MOV thermal limit during locked rotor conditions. However, the calculation
methodology did not consider the design function of jogging/throttling the MOVs in sizing the
TOL protective devices. TOL sizing calculations only addressed the MOV thermal limit
function and the capability to recover from a mis-positioned MOV. Further, the team noted
that there was not operator guidance or documented limitations regarding the maximum
number of times each MOV can be cycled. As a result, the safety function of the MOVs was
not ensured as the installed TOL protective devices could potentially actuate and cause
spurious or unexpected tripping of the affected MOVs during postulated events. The team
concluded the calculation methodology did not consider the design function that
jogging/throttling MOVs have specific thermal overload performance requirements; and that
sizing the TOLs required a unique I2t evaluation methodology to ensure that the valves
would be able to perform the required number of jogging operations without tripping the
TOLs. The I2t methodology considers specific electrical current values (I) for specific times (t)
as an MOV responds to jogging/throttling demand signals.
NRC Regulatory Guide 1.106 Revision 1, to which NextEra is committed in UFSAR
Sections 1.8, 8.1.5.3 and 8.3.1.1, states in Regulatory Position C.2, that the trip setpoint of
the TOL protection devices should be established with all uncertainties resolved in favor of
completing the safety-related action. NRC Generic Letter 89-10, Supplement 1, provides
additional guidance in Question 15, which states that licensees should review design basis
information for each MOV in the program to identify whether, when and how often an MOV
must be opened or closed.
Because the TOL sizing calculations only addressed the MOV thermal limit function and the
capability to recover from a mis-positioned MOV, the resulting TOL design could have
resulted in a spurious or unexpected actuation of the TOL protective devices and potentially
prevented the MOV from performing a safety function to function during transients and
postulated events.
Corrective Actions: NextEra performed a detailed analysis using the I2t methodology, and
determined an appropriate limit for which the affected emergency feedwater MOVs could be
throttled without adversely affecting the valves. The team reviewed the results and verified
that they bounded the expected number of times operators may cycle these valves, and
current MOV operability was not adversely affected. NextEra also plans on developing
operator guidance regarding limitations and actions associated with the maximum number of
times the affected valves can be throttled.
Corrective Action Reference: AR 02312915
Performance Assessment:
Performance Deficiency: NextEras failure to properly verify or check the adequacy of design,
such as by the performance of design reviews or by the use of alternate or simplified
calculational methods, for several MOVs was a performance deficiency within their ability to
foresee and correct, and which should have been prevented. Specifically, NextEra did not
verify the TOL protective devices on eight safety-related emergency feedwater flow control
MOVs were properly sized to support their safety function of repetitive jogging/throttling
during transients and postulated events.
Screening: The team determined this finding was more than minor because it was associated
with the Design Control attribute of the Mitigating Systems cornerstone and affected the
cornerstone objective of ensuring the availability and reliability of systems that respond to
initiating events to prevent undesirable consequences.
Significance: The team assessed the significance of the finding using IMC 0609.04, Initial
Characterization of Findings, and IMC 0609, Appendix A, Exhibit 2, Mitigating Systems
Screening Questions. The team determined that this finding was a deficiency affecting the
design or qualification of a mitigating structure, system or component, where the structure,
system or component maintained its operability or functionality. Therefore, the team
determined the finding to be of very low safety significance (Green).
Cross-Cutting Aspect: None
Enforcement:
Violation: 10 CFR Part 50, Appendix B, Criterion III, Design Control, requires that design
control measures shall provide for verifying or checking the adequacy of design, such as by
the performance of design reviews, by the use of alternate or simplified calculational
methods, or by the performance of a suitable testing program.
Contrary to the above, as of May 3, 2019, NextEras design control measures did not provide
for verifying or checking the adequacy of design of the TOLs for eight safety-related
emergency feedwater flow control MOVs that had a jogging/throttling design function. As a
result, NextEra could not assure the affected MOVs could perform their design safety
function.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with
Section 2.3.2.a of the Enforcement Policy.
Inadequate 4kV Breaker Testing
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
Open
None
The team identified a finding of very low safety significance (Green) involving a Non-Cited
Violation of 10 CFR Part 50, Appendix B, Criterion XI, Test Control, in that NextEras test
program did not assure that all testing required to demonstrate that structures, systems, and
components will perform satisfactorily in service in accordance with written test procedures
that incorporate the requirements and acceptance limits contained in applicable design
documents. Specifically, NextEras six-year inspection, testing and preventive maintenance
procedure for 4kV safety-related breakers did not perform as-found electrical testing for
breaker functions prior to performing preventive maintenance activities. As such, breaker
degradation while in service may not be identified during the subsequent testing, and could
prevent the identification of deterioration toward an unacceptable condition.
Description: The team reviewed NextEras activities associated with preventive maintenance
and testing of safety-related 4kV breakers. In particular, the team evaluated whether the
breaker testing activities were capable of detecting breaker degradation.
As documented in UFSAR Section 8.1.5.2, NextEra is committed to IEEE 308-1971,
Standard Criteria for Class IE Electric Systems for Nuclear Power Generating Stations, and
IEEE Standard 338-1975, Standard Criteria for the Periodic Testing of Nuclear Power
Generating Station Class 1E Power and Protection Systems. IEEE 308-1971 states that
tests shall be performed at scheduled intervals to detect the deterioration of the system
toward an unacceptable condition (Section 6.3, Periodic Equipment Tests); and IEEE
Standard 338-1975, states that functional tests shall assure that the tested equipment is
capable of performing its design function (Section 6.3.2, Functional Tests). The team noted
that NextEra's 4kV power circuit breaker maintenance procedure LX0558.01 4.16kV Breaker
Inspection, Testing and PM, which is performed on a six-year frequency, did not perform as-
found electrical testing for breaker functions, such as breaker timing, and reduced voltage
testing of the trip/close coils prior to inspecting, cleaning, and lubricating the
breakers. NextEra implemented the mechanical and electrical portions of the procedure
separately and sequentially. The team reviewed the procedure and noted the mechanical
portion of the activity was preventive maintenance (inspecting, cleaning, lubricating) and was
typically performed prior to the electrical/testing portion. The team determined that the nature
and sequence of the activities pre-conditioned the breakers prior to performing the
electrical/testing part of the procedure. Since there was no as-found testing performed prior
to the preventive maintenance, the team concluded the sequence of the activities performed
could mask breaker degradation and prevent the identification of deterioration toward an
unacceptable condition as specified in IEEE 308-1971 and 338-1975.
In addition to the IEEE 308-1971 and 338-1975 standards, the team noted NRC Information Notice 97-16, Preconditioning of Plant SSCs before ASME Code In-service Testing or
Technical Specification Surveillance addressed this issue. Specifically, the document
discussed instances where a surveillance procedure contained instructions requiring
technicians to inspect, clean, and lubricate several breakers before performing the as-found
testing of several breaker functions; but since those functions could have been affected by
the cleaning and lubrication, the test results did not represent the as-found condition of the
breakers.
Corrective Actions: NextEra plans to evaluate their 4kV breaker preventive maintenance and
testing process to ensure as-found testing is appropriately performed. The team verified
there were no instances where the affected 4kV breakers had significantly degraded toward
unacceptable performance notwithstanding the lack of as-found testing.
Corrective Action Reference: AR 02312582
Performance Assessment:
Performance Deficiency: NextEras failure to assure that testing required to demonstrate that
structures, systems, and components will perform satisfactorily in service in accordance with
written test procedures that incorporate the requirements and acceptance limits contained in
applicable design documents was a performance deficiency within their ability to foresee and
correct, and which should have been prevented. Specifically, NextEra did not perform
periodic equipment tests in a manner such that they would effectively detect the deterioration
of the equipment toward an unacceptable condition.
Screening: The team determined this finding was more than minor because it was associated
with the Equipment Performance attribute of the Mitigating Systems cornerstone and affected
the cornerstone objective of ensuring the availability and reliability of systems that respond to
initiating events to prevent undesirable consequences. The finding was also more than minor
because if left uncorrected, it would have the potential to lead to a more significant safety
concern.
Significance: The team assessed the significance of the finding using IMC 0609.04, Initial
Characterization of Findings, and IMC 0609, Appendix A, Exhibit 2, Mitigating Systems
Screening Questions. The team determined that this finding was not a deficiency affecting
the design or qualification of a mitigating structure, system or component, did not represent a
loss of system and/or function, and did not represent an actual loss of function. Therefore,
the team determined the finding to be of very low safety significance (Green).
Cross-Cutting Aspect: None
Enforcement:
Violation: 10 CFR Part 50, Appendix B, Criterion XI, Test Control, requires that test program
shall be established to assure that all testing required to demonstrate that structures,
systems, and components will perform satisfactorily in service is identified and performed in
accordance with written test procedures which incorporate the requirements and acceptance
limits contained in applicable design documents.
Contrary to the above, as of May 3, 2019, NextEra did not assure that all testing required to
demonstrate that structures, systems, and components will perform satisfactorily in service in
accordance with written test procedures which incorporate the requirements and acceptance
limits contained in applicable design documents. Specifically, NextEras six-year inspection,
testing and preventive maintenance procedure for 4kV safety-related breakers did not
perform as-found electrical testing for breaker functions prior to performing preventive
maintenance activities. As such, breaker degradation while in service may not have been
identified during the subsequent testing and could prevent the identification of deterioration
toward an unacceptable condition as specified by industry standards.
Enforcement Action: This violation is being treated as an non-cited violation, consistent with
Section 2.3.2.a of the Enforcement Policy.
Survivability of Equipment during a Postulated Design Basis Accident Coincident with
Degraded Offsite Power System Voltage
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
Open
None
The team identified a finding of very low safety significance (Green) involving a Non-Cited
Violation of 10 CFR Part 50, Appendix B, Criterion III, Design Control, in that NextEra did
not verify or check the adequacy of design for setting thermal overload (TOL) protective
devices, such as by the performance of design reviews, by the use of alternate or simplified
calculational methods, or by the performance of a suitable testing program. Specifically,
NextEra did not ensure that TOL protective device settings for specific motor-operated valves
(MOVs) would prevent safety-related loads from becoming damaged or unavailable during a
postulated design basis event involving a loss-of-coolant accident coincident with a degraded
voltage of the offsite power supply system.
Description: The team evaluated the Seabrook design related to a postulated design basis
event coincident with a degraded voltage of the offsite power supply system. In particular, the
team evaluated whether safety-related equipment, which would automatically block load
during such an event, was properly designed and maintained to ensure the equipment would
function as expected. During the postulated scenario, it is assumed that voltage would
remain degraded (less than the second level undervoltage setpoint but above the lower, loss
of voltage setpoint) until the associated time delay of about 11 seconds would ultimately
transfer the electrical power supply to the onsite power system automatically.
The team determined UFSAR Section 8.3.1.1.b.4.(b) stated if the second level undervoltage
protection activation occurs coincidentally with an accident signal, the unit auxiliary
transformer and reserve auxiliary transformer incoming line breakers are automatically tripped
after a time delay to prevent spurious operation due to transients such as starting of large
motors. That scenario would result in a total loss of voltage to the 4kV bus. That action, in
turn, would result in connecting to and sequencing onto the associated emergency diesel
generator.
NRC Branch Technical Position PSB-1, Adequacy of Station Electric Distribution System
Voltages, dated July 1981, stated in part that the time delay associated with the second level
of undervoltage protection should be of limited duration such that the permanently connected
Class 1E loads will not be damaged.
NRC Regulatory Issue Summary (RIS) 2011-12, Revision 1, Adequacy of Station Electric
Distribution System Voltages, was issued to clarify the NRC staffs technical position on
existing requirements. RIS 2011-12 stated the time delay (at which the Class 1E buses
should automatically separate from the offsite power supply) chosen should be optimized to
ensure that permanently connected Class 1E loads are not damaged under sustained
degraded voltage conditions, such as a sustained degraded voltage below the degraded
voltage relay setting for the duration of the time delay setting.
NRC Regulatory Guide 1.106 Revision 1, to which NextEra is committed in UFSAR Sections
1.8 and 8.1.5.3, stated in Regulatory Position C.2, the trip setpoint of the TOL protection
devices should be established with all uncertainties resolved in favor of completing the safety-
related action.
The team determined NextEra did not ensure that safety-related MOV loads that would
require starting during a postulated accident coincident with a degraded grid condition
(second level undervoltage protection), had been verified to ensure the associated MOV
protective devices (i.e., TOLs) would not trip so as to complete the associated safety-related
action. The team observed in calculation 9763-3-ED-00-28-F-CALC_009, minimum trip times
at a locked rotor condition were not evaluated to ensure the safety function would be met if an
MOV stalled as the result of a degraded voltage condition. In particular, NextEra did not
ensure that the TOL design for the associated 17 MOVs that would block load in that scenario
were adequate to ensure the MOV safety functions would be accomplished for this scenario
(i.e., the MOVs could have been subject to a transient degraded voltage, and possibly stall
under certain conditions).
In response to the team's questions, NextEra staff demonstrated that the 4kV emergency
buses were historically operated well above the degraded voltage relay setpoint, and have
not seen a sustained undervoltage condition. In addition, the offsite power system was
historically maintained above its rated 345kV voltage level. Operating procedure controls
have been in place, and NextEra confirmed actual offsite power voltage levels have been
functional and adequate to ensure the affected components and systems were not adversely
impacted by this finding (five year operating history reviewed). In considering this issue,
NextEra staff concluded that full qualification was not demonstrated. In accordance with their
procedures, NextEra staff completed a prompt operability determination and developed
interim actions pending final resolution of this issue. The team discussed the technical details
and reviewed NextEras analyses and prompt operability determination, and found NextEras
actions to be reasonable and appropriate.
Corrective Actions: NextEra staff performed detailed analyses and completed a prompt
operability determination in response to this issue. Several compensatory interim actions
were implemented to ensure that plant operators would take appropriate proactive actions
based on specific conditions, including direction to declare both offsite power sources
inoperable and entering the applicable technical specifications in the event Seabrook is
notified of a post-contingent voltage condition of less than 345kV. Post-contingent voltage is
the calculated voltage to which the grid would degrade in the event of a trip of
Seabrook. Plant operators will also implement an additional action if the grid degrades further
to immediately energize the two safety-related 4kV buses from the emergency diesel
generators to ensure a degraded grid condition will not adversely affect the specific MOVs
powered from safety buses. NextEra plans to implement additional, permanent corrective
actions based on the results of their continuing evaluation of this issue.
Corrective Action Reference: AR 02312943
Performance Assessment:
Performance Deficiency: NextEras failure to properly verify or check the adequacy of design,
such as by the performance of design reviews or by the use of alternate or simplified
calculational methods, for 17 MOVs that are block loaded was a performance deficiency
within their ability to foresee and correct, and which should have been prevented. Specifically,
NextEra did not properly size TOL protective devices for 17 MOVs that would be required to
operate during a postulated design basis event coincident with a degraded voltage
condition. As a result, NextEra did not demonstrate assurance that the MOVs would not
become damaged or rendered unavailable during the postulated scenario.
Screening: The team determined this finding was more than minor because it was associated
with the Design Control attribute of the Mitigating Systems cornerstone and affected the
cornerstone objective of ensuring the availability, reliability and capability of systems that
respond to initiating events to prevent undesirable consequences.
Significance: The team assessed the significance of the finding using IMC 0609.04, Initial
Characterization of Findings, and IMC 0609, Appendix A, Exhibit 2, Mitigating Systems
Screening Questions. The team determined that this finding was a deficiency affecting the
design or qualification of a mitigating structure, system or component, where the structure,
system or component maintained its operability or functionality. While this issue involved the
qualification of several TOL protective devices during a particular degraded grid condition
coincident with postulated design basis accident scenarios described in Chapter 15 (Accident
Analyses) of the UFSAR, the affected MOVs were determined to be capable of performing
their safety function, given the numerous equipment failures, conservative assumptions and
specific system configurations that would have to occur to cause a deterministic system
failure. Therefore, the team determined the finding to be of very low safety significance
(Green).
Cross-Cutting Aspect: None
Enforcement:
Violation: 10 CFR Part 50, Appendix B, Criterion III, Design Control, requires that design
control measures shall provide for verifying or checking the adequacy of design, such as by
the performance of design reviews, by the use of alternate or simplified calculational
methods, or by the performance of a suitable testing program.
Contrary to the above, as of May 3, 2019, NextEras design control measures did not provide
for verifying or checking the adequacy of design to ensure connected Class 1E loads would
not be damaged or become unavailable for a postulated design basis event coincident with a
degraded voltage condition.
Enforcement Action: This violation is being treated as an non-cited violation, consistent with
Section 2.3.2.a of the Enforcement Policy.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On May 3, 2019, the team presented the preliminary results of the Design Bases
Assurance Inspection to Mr. Eric McCartney, Site Vice President, and other members of
NextEra staff. After further in-office review, the final results of this inspection were
presented to Mr. McCartney and the other NextEra staff via telephone on June 5, 2019.
Documents Reviewed
Calculations
4.3.07-12F, PCCW Head Tank Overflow and Pump Suction Line Sizes and Pump NPSH
Analysis, Revision 4
6.01.42.01, Control Building Elevation 21-6 and 50-0 4kV Switchgear Areas, Battery Rooms,
MG Set Rooms and Cable Spreading Room Ventilation, Revision 7
9763-3-ED-00-01-F, Short Circuit Current Calculation, Revision 9
9763-3-ED-00-02-F, Voltage Regulation, Revision 14
9763-3-ED-00-23-F, Medium Voltage Protective Relay Coordination, Revision 6
9763-3-ED-00-28-F, Motor Control Center Protection, Revision 9
9763-3-ED-00-45-F, Control Building Heat Load Calculation, Revision 5
9763-3-ED-00-66-F, Control Circuit Voltage Drop, Revision 5
9763-3-ED-00-83-F, Diesel Generator Loading, Revision 17
C-S-1-20801, Emergency Feedwater System Flow Study, Revision 1
C-S-1-20805, EFW Pump Pressure at Overspeed Trip, Revision 1
C-S-1-20811, EFW System Maximum Operating Pressure, Revision 0
C-S-1-20815, Low Suction Pressure Setpoint for Securing EFW Pumps, Revision 0
C-S-1-20823, EFW Pump IST Performance Requirements, Revision 0
C-S-1-20824, Emergency Feedwater Pump Exhaust Stack - Tornado Missiles, Revision 0
C-S-1-28076, Accidental RCS Depressurization Analysis, Revision 0
C-S-1-28137, Emergency Feedwater System High Flow Isolation Setpoint Analysis, Revision 0
C-S-1-45071, EFW Piping Qualification for Overpressurization, Revision 2
C-S-1-80903, MOV Differential Pressure Calculations, Revision 1
C-S-1-80904, MOV Thrust, Actuator Capability and Torque Switch Setpoint Calculations,
Revision 4
C-S-1-83704, Hydraulic Modeling of PCCW Flow Distribution, Revision 3
C-S-1-83805, CBS-V8/V14 Bonnet Pressure Calculation, Revision 0
C-S-1-83807, Determination of Delta-P, CBS-V8 and V14, Revision 0
C-S-1-83808, Post-LOCA Heatup of Valves CBS-V8 and V14, Revision 0
C-S-1-84213, Appendix R Timing Calculations for Reactor Coolant Inventory Control, Revision 2
C-X-1-21802, Expansion Joint Rupture in the Circulating Water System Located in the Turbine
Building, Revision 3
FP98328, Required Thrust and Weak Link Calculations, Revision B
FP98522, Actuator Sizing and Valve Weak Link Analysis, Revision 0
SBC-128, Technical Specifications, Setpoints and Allowable Values, Revision 17
Engineering Evaluations and Modifications
10CFR50.59 Screen 2004-286, Substitution of Enhanced Operator Action for Turbine Building
Scuppers, Revision 0
10CFR50.59 Screen 2015-50, Fukushima SEPS Components Seismic Upgrades, Revision 0
10CFR50.59 Screen 2015-51, Fukushima SEPS Foundations, Enclosures, and Exhaust
Seismic Upgrades, Revision 0
10CFR50.59 Screen 2016-229, Diesel Air Handling Calculation MSVCS-FAG-09 Revision and
Service Environment Chart Update, Revision 0
DCR 03-002, Supplemental Emergency Power System, 10/17/05
DCR 96-0016, PCCW Heat Exchanger Replacement, Revision 1
DCR 97-0027, Condensate Storage Tank Valve Room Heater, Revision 3
EC 145024, Reconciliation of Methods used for Determining RWST Minimum Submergence
Levels to Preclude Vortexing, Revision 0
EC 145372, EDG Lube Oil High Temperature Trip Setpoint Change, Revision 2
EC 277469, 1-SW-V-4 Running Current Change, Revision 0
EC 282825, Fukushima SEPS Components Seismic Upgrades, Revision 1
EC 283031, Equivalent Design Package for SEPS-DG-2-A Exhaust System Material, Revision 2
EC 284280, Increase in RCS Loop Tavg to Average Tavg Deviation Alarm Setpoint, Revision 0
EC 286883, Replace CC-P-11-A Motor with Rewound Motor, Revision 1
EC 287231, Equivalent Design Package for SEPS-DG-2-A Alternator Guard Cover Plate,
Revision 0
EC 291333, RC-V-122/124 Allowable Closure Time Increase, Revision 0
EE-91-07, Engineering Evaluation 91-07, dated 11/21/91
EQF 600-20-02, Medium Voltage Rewound Large AC Motors Electrical EQ File, Revision 4
LN0196, Inrush Current for a 11NA1 Actuator, 5/2/19
SEC15023-N7747, EQ Supplemental Report for Seabrook 700 HP CCW Pump Motor,
Revision 0
Corrective Action ARs
05-13283
05-11758
00108591
00124852
00157729
00219030
00222271
00222952
00391503
01695541
01761439
01764360
01789108
01862758
02081772
02132107
02150398
02153536
02169116
02169596
02256422
02269582
02270102
02277088
02289002
02291116
02310616
02310694
02310735*
02310800*
02310928
02310929
02310959*
02311034*
02311078*
02311079*
02311107*
02311247*
02311634
02311727*
02311729*
02311731*
02311860*
02311899
02312144
02312150
02312273*
02312286
02312365
02312367*
02312540
02312582*
02312590*
02312617*
02312622*
02312672*
02312764
02312824
02312826
02312876*
02312915*
02312943*
02312974*
02312985
- AR written as a result of this inspection
Design and Licensing Bases
DBD-CC-01, Design Basis Document, Primary Component Cooling Water System, Revision 7
DBD-SW-01, Design Basis Document, Service Water System, Revision 8
LRAP-M021, Closed Cycle Cooling Water System Aging Management Program Basis
Document, Revision 2
SBN-903, Letter to NRC, Resolution of Power System Branch Confirmatory Items, 11/27/85
Drawings
10120177, EDG Voltage Dip Curve, 12/27/77
1-CC-B20205, Primary Component Cooling Loop A Detail, Revision 27
1-NHY-202069, Diesel Generator Building Plans Above Grade General Arrangement,
Revision 16
1-NHY-250000, Data Sheets for Motor-and Air-Operated Valves and Dampers, Revision 86
1-NHY-300219, Service Environment Chart, Revision 29
1-NHY-310002, Electrical Distribution One-Line Diagram, Revision 45
1-NHY-310007, 4160V Switchgear Bus 1-E5 One-Line, Revision 21
1-NHY-310013, 480V Unit Substation Buses E-51 and E-52 One-Line, Revision 22
1-NHY-310024, 480V MCC 1-E512, Revision 31
1-NHY-310027, 480V MCC 1-E521, Revision 34
1-NHY-312070, 4160V Supplemental Emergency Power System One-Line, Revision 1
1-NHY-503270, PCCW Pumps Logic Diagram, Revision 9
1-NHY-506194, Pumps P-11C and P-11A Loop A Control Loop Diagram, Revision 14
FP 23694, Pressures and Temperatures, DG Systems, Revision 1
FP35364, SEPS Generator Enclosure 2A Drawings, Revision 10
PID-1-FW-B20688, Emergency Feedwater System Details, Revision 12
PID-1-SEPS-B20953, SEPS Diesel Generator Fuel System Detail, Revision 0
PID-1-SEPS-B20954, SEPS Diesel Generator Cooling Water System Detail, Revision 1
PID-1-SI-20448, Safety Injection System - Low Head Injection, Revision 15
Procedures
D4702, EFW Pump A Suction Header Pressure Low, Revision 3
D6569, DG A Lube Oil Temp High, Revision 12
D6619, DG B Lube Oil Temp High, Revision 10
D7193, RWST Level LO-LO, Revision 5
E-0, Reactor Trip or Safety Injection, Revision 57
E-1, Loss of Reactor or Secondary Coolant, Revision 44
E-2, Faulted Steam Generator Isolation, Revision 27
E-3, Steam Generator Tube Rupture, Revision 45
ECA-0.0, Loss of all AC Power, Revision 54
EE-04-024, Operator Action Response Times Assumed in the UFSAR, Revision 4
ES 1850.003, Motor-Operated Valve Performance Monitoring, Revision 15
ES-0.2, Natural Circulation Cooldown, Revision 38
ES-1.2, Post LOCA Cooldown and Depressurization, Revision 40
ES-1.3, Transfer to Cold Leg Recirculation, Revision 30
F4232, PCCW Pumps A and C Running, Revision 2
F7494, PCCW Pump A Trip, Revision 5
FR-C.1, Response to Inadequate Core Cooling, Revision 28
FR-H.1, Response to Loss of Secondary Heat Sink, Revision 37
LS0563.58, Trip Check Procedure for EDG Switchgear Breakers, Revision 3
LX0558.01, 4.16kV Breaker Inspection, Testing and PM, Revision 16
ON 1242.01, Loss of Instrument Air, Revision 16
ON 1242.02, Loss of Containment Instrument Air, Revision 13
ON1061.01, Operation of SEPS, Revision 12
ON1061.07, SEPS Maintenance Run, Rev. 7
OS1006.04, Operation of the Containment Spray System, Revision 27
OS1012.03, Primary Component Cooling Water Loop A Operation, Revision 25
OS1026.01, Operation of DG 1A, Revision 30
OS1036.01, Aligning the Emergency Feedwater System for Automatic Initiation, Revision 25
OS1036.04, Emergency Feedwater Pump B Operation, Revision 4
OS1090.05, Component Configuration Control, Revision 74
OS1200.00, Response to Fire or Fire Alarm Actuation, Revision 25
OS1212.01, PCCW System Malfunction, Revision 14
OS1216.01, Degraded Ultimate Heat Sink, Revision 23
OS1246.02, Degraded Vital AC Power, Revision 21
OS1456.99, Cold Leg Recirculation Valve Interlock Surveillance, Revision 0
OX1401.03, RCS Vent Path Block Valve Quarterly, Cold Shutdown, and 18-Month Surveillance
Test, Revision 14
OX1406.13, Containment Recirculation Sump Valve Cold Shutdown Test, Revision 13
OX1436.02, Turbine-Driven EFW Pump Quarterly and Monthly Valve Alignment, Revision 29
OX1436.13, Turbine-Driven EFW Pump Post Cold Shutdown or Post Maintenance Surveillance
and Comprehensive Pump Test, Revision 42
OX1456.81, Operability Testing of IST Valves, Revision 36
OX1456.86, Operability Testing of IST Pumps, Revision 18
OX1461.04, SEPS Monthly Availability Surveillance, Revision 12
SM 7.20, Control of Time Critical Operator Actions and Time Sensitive Actions, Revision 12
SOO 19-002, Interim Guidance for Resetting RMO, Revision 0
Functional, Surveillance and Modification Acceptance Testing
01209321-03, 1-CC-P-11-A Motor Replacement PMT, performed 11/17/16
1-CC-P-11A Pump/Motor Inboard/Outboard Bearing Oil Sample Analysis Trending, 2015-2018
40312073, MOV Diagnostic Testing Summary Report, 1-CBS-V-8, performed 10/13/15
IS1616.420, CC-T-2171A PCCW LP-A Supply Header Temperature Control Calibration,
performed 12/11/17
IS1616.430, CC-T-2197A PCCW LP-A Supply Header Temperature Control Calibration,
performed 10/21/14
LS0558.04, 4.16kV Circuit Breaker Refurbishment, performed 10/8/13
LS0563.151, 1-CC-P-11-A Trip Checks, performed 11/16/16
LS0563.22, Testing of Agastat 120Vac (7000 Series) TDPU Timing Relays, performed 10/19/17
LS0564.34, 4160V Static Motor Testing (1-CC-P-11-A), performed 11/15/16
LS0564.38, 4160V Dynamic Motor Monitoring (1-CC-P-11-A), performed 11/17/16
LX0558.01, 4.16kV Breaker Inspection, Testing and PM (EDE-BKR-06), performed 6/21/17
OS1412.13, PCCW Train A Quarterly Operability, 18-Month Position Indication and
Comprehensive Pump Testing, performed 7/19/18 and 1/23/19
OX1401.03, RCS Vent Path Block Valve Quarterly, Cold Shutdown, and 18-Month Surveillance
Test, performed 6/19/18
OX1426.22, EDG 1A 24-Hour Load Test and Hot Restart Surveillance, performed 11/15/17
OX1426.23, EDG 1B 24-Hour Load Test and Hot Restart Surveillance, performed 1/31/18
OX1426.32, Diesel Generator 1B 36-Month Operability Surveillance, performed 4/25/17
OX1426.34, Diesel Generator 1A 36-Month Operability Surveillance, performed 10/24/18
OX1461.04, SEPS Monthly Availability Surveillance, performed 2/19/19, 3/18/19 and 4/23/19
V1435744, 1-SEPS-DG-2A Engine Sump Analysis, performed 11/6/17
Vendor Documents and Specifications
9763-006-238-5, Specification for Primary Component Cooling Water Pumps, Revision 6
FP 34938, Limitorque Vendor Manual, Revision 26
FP 53455, Primary Component Cooling Pump Vendor Technical Manual, Revision 14
FP35465-16 C808-2, Cummins Engine Company Troubleshooting and Repair Manual, Power
Generation Control Systems, QSK78 Series Engines, Volume 1, 7/30/04
SPEC-E-008, FPL Motor Repair/Refurbishment/ Rewind Requirements Specification,
Revision 11
Miscellaneous
SBK 16-005, Seabrook Nuclear Oversight Report - Maintenance, 9/27/16
SBK 17-003, Seabrook Nuclear Assurance Report - Design Engineering, 6/7/17
SBK 18-003, Seabrook Nuclear Assurance Report - Maintenance, 8/10/18
System Health Report, Diesel Generator System, Q1-2019
System Health Report, Electrical Distribution, Q1-2019
System Health Report, Primary Component Cooling Water, Q4-2018
System Health Report, Supplemental Emergency Power System, Q4-2018
Maintenance Work Orders
01209321
01211490
40207426
40235293
40270599
40312331
40365253
40397424
40397426
40433610
40446081
40490341
40493088
40493090
40493095
40497320
40498960
40498985
40510286
40514497
40531858
40534102
40534290
40539735
40539776
40539778
40547372
40550706
40550718
40584858
40611075
40611076
40611077